Existing hosts capable of hosting guided projectiles require a guided projectile that is electrically and communicatively connected to the host, which may be an aircraft, Unmanned Aerial Vehicle (UAV), helicopter, jet, satellite or ground based tracking system, or other ground, sky, space or water-based vehicle. Such current hosts require the projectile to be powered-on by either the host's or the projectile's internal power, prior to a decision to launch the projectile and during data transfers, such as during the transfer of mission critical data.
Although there are ways to enable such communications to take place without requiring the projectile to be powered-on, it is significantly more difficult to do so utilizing existing single-wire interface umbilical cords, which are already in widespread use on aircraft, between the host aircraft and the guided projectile. It is even more difficult to achieve this objective without limiting any existing interface capabilities.
While it is important to maintain compatibility with legacy systems without limiting their present functionality, using additional or multi contact interface cables, as opposed to continuing with a single cable interface, is also problematic due to such a solution necessitating a more mechanically complex disconnect process at launch, which will often be under adverse conditions.
Furthermore, present single-cable interface data transfer solutions do not allow projectiles to communicate adverse health issues that may warrant aborting a launch or replacing the problematic projectiles prior to a decision to launch over a relatively simple interface, with solutions capable of providing such information requiring multiple connections and a relatively complex disconnection sequence upon launch.
Additionally, modern laser-guided missiles typically rely on a laser designator to “mark” a target. The missile, once launched, searches for a laser-designated target and uses various forms of directional control to reach the designated target. To allow the firing of multiple missiles by various platforms simultaneously, such laser-designators produce a precision controlled laser-pulse having a very specific pulse interval, among other potential characteristics. Each missile is programmed to lock onto only a specific pulse-interval. Such a pulse-interval is typically set during installation of the missile onto the plane, just prior to launch.
On occasion, it may be desirable for a pilot to be able to reprogram a missile to lock onto a different laser designator. While this is possible using relatively sophisticated multi-cable solutions, it is not currently possible over single-cable interfaces. Furthermore, it is not currently possible without turning the missile on prior to launch.
Moreover, the systems of present aircraft are limited in weight, size and power, requiring the additional functionality enabled by any new system, such as pre-launch data transfer and projectile health checks and reports, to place no high power demand on the host aircraft.
Lastly, the aircraft to projectile guidance and arming system interfaces of current single-cable precision guided projectiles do not currently support the transfer of data, such as is required to enable free inertial navigation capability, perform health checks, or change missile codes, such as those used to match a laser guided missile to a laser designator. One example of a precision guided asset is the Advanced Precision Kill Weapon Systems (APKWS).
Any changes to such systems are relatively unworkable unless changes to current cabling, protocols, etc. are minimal, due to the widespread deployment of legacy systems and the high cost of their replacement.
Also, it is important to only enable a missile's power source just prior to, or even just after, launch to conserve the missile's power, which may be very limited. In various missiles, a thermal battery, which cannot be turned off once enabled and may be depleted in a relatively short period of time, may be used, making it even more important to transfer data without enabling the missile's onboard power source.
What is needed, therefore, are techniques for enabling communications between a projectile and command center that would allow the projectile to report adverse health issues prior to a decision to launch, to change missile codes while in flight, and to gain free inertial navigation capability without requiring the projectile to be powered-on by either the host aircraft's or the projectile's own internal power, where the system utilizes existing umbilical cords for communications and does not limit the functionality of existing systems that may also make use of this aircraft-to-projectile connection.